JP2003342615A - Cermet coating method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily and inexpensively coating cermet on the surface of a member being in contact with a molten metal or a molten resin. <P>SOLUTION: This apparatus comprises a nozzle 2 installed in the lowest part of a vessel 1, a stirring device 3 accommodated in the vessel 1, and a heating device 4 around the vessel 1. This coating method comprises accommodating slurry 7 which is a mixture of a cermet powder with a binder consisting of a molten resin in the vessel 1, and moving the vessel 1 parallel with a longitudinal direction of a tapping pin 9 above the tapping pin 9, while rotating the tapping pin 9 in a state of horizontally holding it, and simultaneously sending a compressed air into in the vessel 1 to pressurize the vessel 1. Thereby, the slurry 7 is pushed out from the nozzle 2 and applied in a half solidified state on the surface of the tapping pin 9. Thus coated layer is kept cool and solidified after the coating of the slurry 7 onto the core pin 9 has been finished. Then, the core pin 9 is accommodated in a vacuum furnace and the coating layer is sintered. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cermet coating method and an apparatus used for the same, and more particularly, to an object of enhancing corrosion resistance and wear resistance of a member which comes into contact with molten metal or molten resin in a die casting machine or an injection molding machine. And a method and apparatus for forming a coating layer of cermet on the surface thereof.

[0002]

2. Description of the Related Art Conventionally, a die of a die casting machine for an Al alloy or a die-casting pin for a die has a steel base material made of CVD, PVD or a steel for the purpose of preventing melting damage due to contact with molten metal. Those subjected to surface treatment such as nitriding treatment are widely used. However, in the case of CVD or PVD, since the coating layer is very thin, the coating layer disappears in a short period of time due to wear of the cast product at the time of mold release and erosion of the molten metal, resulting in a short service life. In the case of nitriding treatment,
It becomes unusable in a short period of time due to chipping due to thermal shock, peeling of the nitride layer, abrasion, etc., and the service life is short.

In order to solve the above problems, a mold coated with a cermet having heat shock resistance, wear resistance and Al melting resistance is also used. As a method of coating a cermet on a steel base material, thermal spraying,
There are HIP and CIP. However, in the case of thermal spraying, there is a problem that a large-scale device is required and holes are easily generated in the formed coating layer. In addition, HIP and C
When using IP, it is necessary to prepare an expensive mold,
Manufacturing cost is high.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the conventional coating method, and an object of the present invention is to provide a surface of a member or the like which comes into contact with molten metal or molten resin. Another object of the present invention is to provide a method for coating a cermet, which is simple and low cost, and an apparatus used therefor.

[0005]

The cermet coating method of the present invention is a method for coating the surface of a member to be treated with cermet, which comprises a solvent and a resin in a container connected to the upstream side of a nozzle. A slurry containing cermet powder mixed in a binder is housed, the inside of the container is pressurized to push the slurry out of the nozzle, and the nozzle is relatively moved along the surface of the member to be treated. A coating layer made of cermet is bonded to the surface of the member to be processed by applying the slurry to the surface of the member and then sintering the slurry in a vacuum furnace.

According to the cermet coating method of the present invention, a nozzle and a container having a relatively simple structure can be used when applying the slurry to the surface of the member to be treated. Then, by sintering this slurry in a vacuum furnace, a coating layer made of cermet can be formed on the surface of the member to be treated. According to the method of the present invention, unlike the conventional methods, a large-scale device is not required, and thus the cost of cermet coating can be reduced.

As the binder, a molten resin may be used instead of a resin in which a resin is dissolved. In that case, a slurry is formed by heating the resin and the cermet powder while stirring in the container. In addition, by adjusting the temperature of the slurry at the discharge port of the nozzle, the slurry can be applied to the surface of the member to be processed in a semi-solidified state.

Further, the cermet coating device used for carrying out the above method is a nozzle, a container connected to the upstream side of the nozzle and containing a slurry in which cermet powder is mixed in a binder, and a container inside the container. A pressurizing device for pressurizing the slurry, and a two-dimensional or three-dimensional drive system for relatively moving the nozzle along the surface of the member to be treated, and extruding the slurry from the nozzle by the pressurizing device. The slurry is applied to the surface of the member to be processed.

[0009] Preferably, the nozzle is configured to be attachable to and detachable from the container. With this configuration, it becomes possible to switch the cross-sectional shape of the nozzle outlet to an appropriate shape according to various conditions such as the particle size of the cermet powder and the target thickness of the coating layer. The thickness accuracy can be increased.

Preferably, the container is equipped with a stirring device for stirring the slurry contained therein.

When molten resin is used as the binder, the container is equipped with a stirring device for stirring the slurry and a heating device for heating the slurry.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an outline of an embodiment of a coating apparatus used in the cermet coating method of the present invention. In the figure, 1 is a container, 2 is a nozzle, 3 is a stirring device, 4 is a heating device, 5 is a pressurized air source (pressurizing device), 7 is a slurry, and 9 is a die-casting pin (a member to be treated). ).

The container 1 has a cylindrical body and a conical bottom. A nozzle 2 is attached to the bottom of the container 1. A stirring device 3 rotated by a motor 10 is housed in the container 1. A heating device 4 is attached around the body of the container 1. Pressurized air from the pressurized air source 5 is introduced near the upper end of the container 1.

The container 1 contains a slurry 7 in which a binder made of molten resin is mixed with cermet powder. In this example, the particle size of the cermet powder is 45 to
It is about 150 μm, the resin is acrylic resin, and the diameter of the nozzle 2 is 1.6 mm.

Next, a method of joining a coating layer made of cermet to the surface of the die-cast pin 9 for a mold using this coating apparatus will be described. The casting pin 9 is made of alloy tool steel SKD61, for example.
First, the container 1 is stirred by the stirring device 3 and heated by the heating device 4. As a result, the resin is melted to form the slurry 7 in which the cermet powder is dispersed in the molten resin. As shown in FIG. 1, the rear end portion of the casting pin 9 is attached to the rotary drive device 8 to hold the casting pin 9 horizontally. While rotating the casting pin 9 with the rotation drive device 8,
The container 1 is moved above the casting pin 9 in parallel with the longitudinal direction of the casting pin 9. At the same time, pressurized air is sent from the pressurized air source 5 into the container 1 to pressurize the upper surface of the slurry in the container 1. As a result, the slurry 7 is extruded in the form of threads from the nozzle 2 and applied to the surface of the casting pin 9 in a semi-solidified state.

After the slurry 7 has been applied to the cast pin 9, it is kept cold to solidify the coating layer. Next, the die-cast pin 9 is housed in a vacuum furnace and held at 1110 ° C. for 30 minutes to sinter the coating layer. by this,
A coating layer made of cermet is bonded to the surface of the cast pin 9.

In the above-described embodiment, an example in which pressurized air is used to pressurize the slurry 7 in the container 1 has been shown. However, when the agitator 3 is not used, it is mechanically pressurized by a plunger or the like. May be.

In the above-described embodiment, the nozzle 2 is relatively moved along the surface to be processed of the casting pin 9 by rotating the casting pin 9 and moving the container 1 in parallel. However, for this relative movement, an appropriate two-dimensional or three-dimensional drive system can be adopted according to the shape of the surface to be processed.

[0019]

According to the cermet coating method of the present invention, when applying the slurry to the surface of the member to be treated, it is possible to use a nozzle and a container having a relatively simple structure. Then, by sintering this slurry in a vacuum furnace, a coating layer made of cermet can be formed on the surface of the member to be treated. According to the method of the present invention, unlike the conventional methods, a large-scale device is not required, and thus the cost of cermet coating can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a cermet coating method and a cermet coating apparatus used for the same according to the present invention.

[Explanation of symbols]

1 ... container, 2 ... Nozzle, 3 ... Stirrer, 4 ... Heating device, 5: pressurized air source, 7 ... slurry, 8 ... Rotation drive device, 9 ... Cast pin for mold (member to be treated), 10 ... Motor.

Claims (6)

[Claims] 1. A method for coating the surface of a member to be treated with cermet, comprising storing a slurry prepared by mixing cermet powder with a binder made of a solvent and a resin in a container connected to an upstream side of a nozzle, While pressurizing the inside of the container to push out the slurry from the nozzle, by relatively moving the nozzle along the surface of the member to be processed, the slurry is applied to the surface of the member to be processed, A cermet coating method, wherein a coating layer made of cermet is bonded to the surface of the member to be treated by sintering the slurry in a vacuum furnace. 2. A method for coating the surface of a member to be treated with cermet, comprising storing a slurry prepared by mixing cermet powder with a binder made of molten resin in a container connected to an upstream side of a nozzle, By pressing the inside of the container to push out the slurry from the nozzle and moving the nozzle relatively along the surface of the member to be processed, the slurry is applied to the surface of the member to be processed in a semi-solidified state. Next, the coating layer made of cermet is bonded to the surface of the member to be treated by sintering the slurry in a vacuum furnace. 3. A nozzle, a container that is connected to the upstream side of the nozzle and that stores a slurry in which cermet powder is mixed in a binder, a pressurizing device that pressurizes the slurry in the container, and a member that processes the nozzle. A two-dimensional or three-dimensional drive system for relatively moving along the surface of, and applying the slurry to the surface of the member to be processed by pushing out the slurry from the nozzle by the pressurizing device. A cermet coating device characterized by. 4. The cermet coating apparatus according to claim 3, wherein the nozzle is configured to be attachable to and detachable from the container. 5. The cermet coating apparatus according to claim 3, wherein the container is provided with a stirring device for stirring the slurry. 6. The container according to claim 3, further comprising a heating device for heating the slurry.
Or the cermet coating device according to any one of 5 above.